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#include "PMW3901.hpp"

static constexpr uint32_t TIME_us_TSWW = 11; //  - actually 10.5us

PMW3901::PMW3901(I2CSPIBusOption bus_option, int bus, int devid, enum Rotation yaw_rotation, int bus_frequency,
		 spi_mode_e spi_mode) :
	SPI(DRV_FLOW_DEVTYPE_PMW3901, MODULE_NAME, bus, devid, spi_mode, bus_frequency),
	I2CSPIDriver(MODULE_NAME, px4::device_bus_to_wq(get_device_id()), bus_option, bus),
	_sample_perf(perf_alloc(PC_ELAPSED, "pmw3901: read")),
	_comms_errors(perf_alloc(PC_COUNT, "pmw3901: com err")),
	_yaw_rotation(yaw_rotation)
{
}

PMW3901::~PMW3901()
{
	// free perf counters
	perf_free(_sample_perf);
	perf_free(_comms_errors);
}

int
PMW3901::sensorInit()
{
	uint8_t data[5] {};

	// Power on reset
	writeRegister(0x3A, 0x5A);
	usleep(5000);

	// Reading the motion registers one time
	readRegister(0x02, &data[0], 1);
	readRegister(0x03, &data[1], 1);
	readRegister(0x04, &data[2], 1);
	readRegister(0x05, &data[3], 1);
	readRegister(0x06, &data[4], 1);

	usleep(1000);

	// set performance optimization registers
	// from PixArt PMW3901MB Optical Motion Tracking chip demo kit V3.20 (21 Aug 2018)
	unsigned char v = 0;
	unsigned char c1 = 0;
	unsigned char c2 = 0;

	writeRegister(0x7F, 0x00);
	writeRegister(0x55, 0x01);
	writeRegister(0x50, 0x07);
	writeRegister(0x7f, 0x0e);
	writeRegister(0x43, 0x10);

	readRegister(0x67, &v, 1);

	// if bit7 is set
	if (v & (1 << 7)) {
		writeRegister(0x48, 0x04);

	} else {
		writeRegister(0x48, 0x02);
	}

	writeRegister(0x7F, 0x00);
	writeRegister(0x51, 0x7b);
	writeRegister(0x50, 0x00);
	writeRegister(0x55, 0x00);

	writeRegister(0x7F, 0x0e);
	readRegister(0x73, &v, 1);

	if (v == 0) {
		readRegister(0x70, &c1, 1);

		if (c1 <= 28) {
			c1 = c1 + 14;

		} else {
			c1 = c1 + 11;
		}

		if (c1 > 0x3F) {
			c1 = 0x3F;
		}

		readRegister(0x71, &c2, 1);
		c2 = ((unsigned short)c2 * 45) / 100;

		writeRegister(0x7f, 0x00);
		writeRegister(0x61, 0xAD);
		writeRegister(0x51, 0x70);
		writeRegister(0x7f, 0x0e);
		writeRegister(0x70, c1);
		writeRegister(0x71, c2);
	}

	writeRegister(0x7F, 0x00);
	writeRegister(0x61, 0xAD);
	writeRegister(0x7F, 0x03);
	writeRegister(0x40, 0x00);
	writeRegister(0x7F, 0x05);
	writeRegister(0x41, 0xB3);
	writeRegister(0x43, 0xF1);
	writeRegister(0x45, 0x14);
	writeRegister(0x5B, 0x32);
	writeRegister(0x5F, 0x34);
	writeRegister(0x7B, 0x08);
	writeRegister(0x7F, 0x06);
	writeRegister(0x44, 0x1B);
	writeRegister(0x40, 0xBF);
	writeRegister(0x4E, 0x3F);
	writeRegister(0x7F, 0x08);
	writeRegister(0x65, 0x20);
	writeRegister(0x6A, 0x18);
	writeRegister(0x7F, 0x09);
	writeRegister(0x4F, 0xAF);
	writeRegister(0x5F, 0x40);
	writeRegister(0x48, 0x80);
	writeRegister(0x49, 0x80);
	writeRegister(0x57, 0x77);
	writeRegister(0x60, 0x78);
	writeRegister(0x61, 0x78);
	writeRegister(0x62, 0x08);
	writeRegister(0x63, 0x50);
	writeRegister(0x7F, 0x0A);
	writeRegister(0x45, 0x60);
	writeRegister(0x7F, 0x00);
	writeRegister(0x4D, 0x11);
	writeRegister(0x55, 0x80);
	writeRegister(0x74, 0x21);
	writeRegister(0x75, 0x1F);
	writeRegister(0x4A, 0x78);
	writeRegister(0x4B, 0x78);
	writeRegister(0x44, 0x08);
	writeRegister(0x45, 0x50);
	writeRegister(0x64, 0xFF);
	writeRegister(0x65, 0x1F);
	writeRegister(0x7F, 0x14);
	writeRegister(0x65, 0x67);
	writeRegister(0x66, 0x08);
	writeRegister(0x63, 0x70);
	writeRegister(0x7F, 0x15);
	writeRegister(0x48, 0x48);
	writeRegister(0x7F, 0x07);
	writeRegister(0x41, 0x0D);
	writeRegister(0x43, 0x14);
	writeRegister(0x4B, 0x0E);
	writeRegister(0x45, 0x0F);
	writeRegister(0x44, 0x42);
	writeRegister(0x4C, 0x80);
	writeRegister(0x7F, 0x10);
	writeRegister(0x5B, 0x02);
	writeRegister(0x7F, 0x07);
	writeRegister(0x40, 0x41);
	writeRegister(0x70, 0x00);

	px4_usleep(10000); // delay 10ms

	writeRegister(0x32, 0x44);
	writeRegister(0x7F, 0x07);
	writeRegister(0x40, 0x40);
	writeRegister(0x7F, 0x06);
	writeRegister(0x62, 0xF0);
	writeRegister(0x63, 0x00);
	writeRegister(0x7F, 0x0D);
	writeRegister(0x48, 0xC0);
	writeRegister(0x6F, 0xD5);
	writeRegister(0x7F, 0x00);
	writeRegister(0x5B, 0xA0);
	writeRegister(0x4E, 0xA8);
	writeRegister(0x5A, 0x50);
	writeRegister(0x40, 0x80);

	return PX4_OK;
}

int
PMW3901::init()
{
	// get yaw rotation from sensor frame to body frame
	param_t rot = param_find("SENS_FLOW_ROT");

	if (rot != PARAM_INVALID) {
		int32_t val = 0;
		param_get(rot, &val);

		_yaw_rotation = (enum Rotation)val;
	}

	/* For devices competing with NuttX SPI drivers on a bus (Crazyflie SD Card expansion board) */
	SPI::set_lockmode(LOCK_THREADS);

	/* do SPI init (and probe) first */
	if (SPI::init() != OK) {
		return PX4_ERROR;
	}

	sensorInit();

	_previous_collect_timestamp = hrt_absolute_time();

	start();

	return PX4_OK;
}

int
PMW3901::probe()
{
	uint8_t data[2] {};

	readRegister(0x00, &data[0], 1); // chip id

	// Test the SPI communication, checking chipId and inverse chipId
	if (data[0] == 0x49) {
		return OK;
	}

	// not found on any address
	return -EIO;
}

int
PMW3901::readRegister(unsigned reg, uint8_t *data, unsigned count)
{
	uint8_t cmd[5];	// read up to 4 bytes

	cmd[0] = DIR_READ(reg);

	int ret = transfer(&cmd[0], &cmd[0], count + 1);

	if (OK != ret) {
		perf_count(_comms_errors);
		DEVICE_LOG("spi::transfer returned %d", ret);
		return ret;
	}

	memcpy(&data[0], &cmd[1], count);

	return ret;
}

int
PMW3901::writeRegister(unsigned reg, uint8_t data)
{
	uint8_t cmd[2]; 						// write 1 byte
	int ret;

	cmd[0] = DIR_WRITE(reg);
	cmd[1] = data;

	ret = transfer(&cmd[0], nullptr, 2);

	if (OK != ret) {
		perf_count(_comms_errors);
		DEVICE_LOG("spi::transfer returned %d", ret);
		return ret;
	}

	px4_usleep(TIME_us_TSWW);

	return ret;
}

void
PMW3901::RunImpl()
{
	perf_begin(_sample_perf);

	int16_t delta_x_raw = 0;
	int16_t delta_y_raw = 0;
	uint8_t qual = 0;
	float delta_x = 0.0f;
	float delta_y = 0.0f;

	uint64_t timestamp = hrt_absolute_time();
	uint64_t dt_flow = timestamp - _previous_collect_timestamp;
	_previous_collect_timestamp = timestamp;

	_flow_dt_sum_usec += dt_flow;

	readMotionCount(delta_x_raw, delta_y_raw, qual);

	if (qual > 0) {
		_flow_sum_x += delta_x_raw;
		_flow_sum_y += delta_y_raw;
		_flow_sample_counter ++;
		_flow_quality_sum += qual;
	}

	// returns if the collect time has not been reached
	if (_flow_dt_sum_usec < _collect_time) {
		return;
	}

	delta_x = (float)_flow_sum_x / 385.0f;		// proportional factor + convert from pixels to radians
	delta_y = (float)_flow_sum_y / 385.0f;		// proportional factor + convert from pixels to radians

	optical_flow_s report{};
	report.timestamp = timestamp;

	report.pixel_flow_x_integral = static_cast<float>(delta_x);
	report.pixel_flow_y_integral = static_cast<float>(delta_y);

	// rotate measurements in yaw from sensor frame to body frame according to parameter SENS_FLOW_ROT
	float zeroval = 0.0f;
	rotate_3f(_yaw_rotation, report.pixel_flow_x_integral, report.pixel_flow_y_integral, zeroval);
	rotate_3f(_yaw_rotation, report.gyro_x_rate_integral, report.gyro_y_rate_integral, report.gyro_z_rate_integral);

	report.frame_count_since_last_readout = _flow_sample_counter;	// number of frames
	report.integration_timespan = _flow_dt_sum_usec; 	// microseconds

	report.sensor_id = 0;
	report.quality = _flow_sample_counter > 0 ? _flow_quality_sum / _flow_sample_counter : 0;


	/* No gyro on this board */
	report.gyro_x_rate_integral = NAN;
	report.gyro_y_rate_integral = NAN;
	report.gyro_z_rate_integral = NAN;

	// set (conservative) specs according to datasheet
	report.max_flow_rate = 5.0f;       // Datasheet: 7.4 rad/s
	report.min_ground_distance = 0.1f; // Datasheet: 80mm
	report.max_ground_distance = 30.0f; // Datasheet: infinity

	_flow_dt_sum_usec = 0;
	_flow_sum_x = 0;
	_flow_sum_y = 0;
	_flow_sample_counter = 0;
	_flow_quality_sum = 0;

	_optical_flow_pub.publish(report);

	perf_end(_sample_perf);
}

int
PMW3901::readMotionCount(int16_t &deltaX, int16_t &deltaY, uint8_t &qual)
{
	uint8_t data[12] = { DIR_READ(0x02), 0, DIR_READ(0x03), 0, DIR_READ(0x04), 0,
			     DIR_READ(0x05), 0, DIR_READ(0x06), 0, DIR_READ(0x07), 0
			   };

	int ret = transfer(&data[0], &data[0], 12);

	if (OK != ret) {
		qual = 0;
		perf_count(_comms_errors);
		DEVICE_LOG("spi::transfer returned %d", ret);
		return ret;
	}

	deltaX = ((int16_t)data[5] << 8) | data[3];
	deltaY = ((int16_t)data[9] << 8) | data[7];

	// If the reported flow is impossibly large, we just got garbage from the SPI
	if (deltaX > 240 || deltaY > 240 || deltaX < -240 || deltaY < -240) {
		qual = 0;

	} else {
		qual = data[11];
	}

	ret = OK;

	return ret;
}

void
PMW3901::start()
{
	// schedule a cycle to start things
	ScheduleOnInterval(PMW3901_SAMPLE_INTERVAL, PMW3901_US);
}

void
PMW3901::stop()
{
	ScheduleClear();
}

void
PMW3901::print_status()
{
	I2CSPIDriverBase::print_status();
	perf_print_counter(_sample_perf);
	perf_print_counter(_comms_errors);
}